Penampang membujur akar | Zona pertumbuhan akar
Summary
TLDRThis educational video delves into the anatomy of plant roots, focusing on the root cap, which protects the meristematic cells and aids in soil penetration. It discusses the root cap's composition, including columella and peripheral cells, and their roles in response to gravity and root growth. The video also covers the mucigel, a protective layer that lubricates the root tip for easier soil penetration and absorbs water and minerals. Further, it explains the primary growth zones of the root: the meristematic zone for cell division, the elongation zone where cells lengthen, and the maturation zone where cells specialize. The video concludes with an overview of root tissues, including the epidermis, cortex, endodermis, and the central cylinder containing xylem and phloem.
Takeaways
- 🌱 The video discusses the anatomy of the root tip, specifically the structure and function of the root cap.
- 🛡️ The root cap serves as a protective layer for the meristematic cells, allowing the root to penetrate the soil without damage.
- 🌿 It is composed of two types of cells: columella cells, which respond to gravity, and peripheral cells, which help in soil penetration and secrete mucigel.
- 💧 Mucigel is a protective layer that prevents desiccation, lubricates the root for easier soil penetration, and aids in the absorption of water and minerals.
- 📈 The root tip contains three primary growth zones: the meristematic zone for cell division, the elongation zone where cells increase in length, and the maturation zone where cells specialize.
- 🌳 The meristematic zone includes the apical meristem, which produces new cells, and the primary meristem, which gives rise to various tissues.
- 🌱 The elongation zone is where cells rapidly increase in length, contributing to the root's growth downwards.
- 🔍 The maturation zone is where cells differentiate into specialized tissues, forming the various tissues of the root.
- 🌿 The outermost layer of the root is the epidermis, which develops from the protoderm and forms root hairs for increased absorption surface.
- 🍃 The cortex, located beneath the epidermis, consists of parenchyma cells that store carbohydrates and facilitate water and mineral absorption.
- 🔄 The endodermis is a tightly packed cell layer with thin, semipermeable walls that regulate water and nutrient uptake into the vascular tissues.
Q & A
What is the function of the root cap in plants?
-The root cap serves to protect the meristematic cells from damage as they divide and grow, allowing the plant to penetrate the soil without injury. It also helps to anchor the plant firmly into the soil.
What are the two types of cells that make up the root cap?
-The two types of cells in the root cap are columella cells, which are columnar and respond to gravity, and peripheral cells, which are derived from the root cap and will mostly shed off as the root penetrates the soil.
What is the role of mucigel in the root tip?
-Mucigel is a protective layer on the root tip composed of polysaccharides that contain sugars, organic acids, vitamins, enzymes, and amino acids. It serves to protect the root from desiccation, act as a lubricant to facilitate soil penetration, and aid in the absorption of water and minerals from the soil.
What are the three primary growth zones of a root?
-The three primary growth zones of a root are the meristematic zone, where cells divide rapidly; the elongation zone, where cells increase in length; and the maturation zone, where cells specialize in structure and function.
What is the function of the apical meristem in the root?
-The apical meristem generates new cells for the root cap and replaces the cap cells that are shed as the root grows into the soil. It also contains a quiescent center that acts as a reserve for meristem recovery in case of damage.
How does the elongation zone contribute to root growth?
-In the elongation zone, cells increase in length up to ten times their original size, which pushes the meristematic cells forward, allowing the root to extend.
What happens in the maturation zone of the root?
-In the maturation zone, cells undergo specialization in structure and function, completing their differentiation process to form various tissues.
What is the epidermis in the root and what is its function?
-The epidermis is the outer layer of the root that originates from the protoderm. It is composed of thin-walled cells and plays a role in the formation of root hairs, which increase the surface area for water and mineral absorption from the soil.
What is the function of the cortex in the root?
-The cortex is composed of parenchyma cells that store carbohydrates and absorb water and minerals from the root hairs. It also contains plasmodesmata, which are channels that allow water to pass through the cortex cells.
What is the endodermis and how does it function in the root?
-The endodermis is a layer of closely packed cells with thin, semipermeable walls that regulate the intake of water into the vascular tissue, the xylem, and also selects the nutrients that will be absorbed by the plant. In mature endodermal cells, a casparian strip of suberin forms a ring-like barrier.
What are the functions of xylem and phloem in the root?
-The xylem in the root is responsible for transporting water and minerals to the leaves, while the phloem distributes the products of photosynthesis throughout the plant body.
Outlines
🌱 Anatomy of the Root Cap
This paragraph discusses the anatomy of the root tip, specifically focusing on the root cap, which is the outermost protective layer of the root. The root cap consists of two types of cells: columnar cells that respond to gravity and help the root grow downwards, and peripheral cells that provide protection and lubrication as the root penetrates the soil. The paragraph also explains the role of mucigel, a protective layer secreted by the root that aids in moisture retention and penetration through the soil. Furthermore, it delves into the primary growth zones of the root, including the meristematic zone where cells divide rapidly, the elongation zone where cells increase in length, and the maturation zone where cells differentiate to form various tissues.
🌿 Types of Tissues in Root Zones
The second paragraph elaborates on the different types of tissues found in the root zones. It begins with the epidermis, the outermost layer that develops from the protoderm and is responsible for the formation of root hairs, which aid in water and mineral absorption. The cortex, composed of parenchyma cells, stores carbohydrates and absorbs water and minerals from the root hairs. The endodermis, characterized by tightly packed cells with thin, semipermeable walls, regulates the entry of water into the vascular tissues. The central cylinder, or stele, contains xylem and phloem vessels, with xylem responsible for water and mineral transport and phloem for distributing the products of photosynthesis. The paragraph also distinguishes between the dicotyledonous and monocotyledonous roots in terms of the arrangement of xylem and phloem. The video concludes with a brief acknowledgment and a transition to the next topic.
Mindmap
Keywords
💡Akar
💡Tudung Akar
💡Meristem
💡Columella
💡Sel Perifer
💡Mucigel
💡Zona Pembelahan Sel
💡Zona Pemanjangan
💡Zona Pematangan
💡Epidermis
💡Korteks
💡Endodermis
💡Stelle
Highlights
Introduction to the anatomy of the root hair, the outermost part of the root.
The root cap, or 'tudung akar,' protects the meristematic cells during division.
Root cap cells can penetrate the soil without damage and anchor the plant firmly.
The root cap is composed of two types of cells: columnar cells and peripheral cells.
Columnar cells contain amyloplasts and respond to gravity, aiding in downward growth.
Peripheral cells are derived from the root cap's epidermal cells and often shed as the root penetrates the soil.
Peripheral cells secrete mucigel, a protective layer that prevents desiccation and aids in soil penetration.
Mucigel is composed of polysaccharides, hydrated substances, sugars, organic vitamins, enzymes, and amino acids.
Behind the root cap are the primary growth zones of the root.
The primary growth zones include the meristematic zone, elongation zone, and maturation zone.
The meristematic zone is where rapid cell division occurs, led by the apical meristem.
The elongation zone is where cells increase in length, pushing the root forward.
The maturation zone is where cells specialize in structure and function.
Epidermis, derived from the protoderm, forms the outer layer of the root and produces root hairs.
Cortex, composed of parenchyma cells, stores carbohydrates and absorbs water and minerals from root hairs.
Endodermis, with closely packed cells and a semipermeable membrane, regulates water intake and selects nutrients.
The central cylinder, or stele, develops from the procambium and contains xylem and phloem.
Xylem transports water and minerals to the leaves, while phloem distributes photosynthesis products.
In dicot roots, xylem is star-shaped or X-shaped, while in monocot roots, xylem and phloem are interspersed.
The video concludes with a summary and an invitation to the next video, emphasizing the educational value of the content.
Transcripts
Halo assalamualaikum warahmatullahi
wabarakatuh salam sejahtera untuk kita
semua selamat datang di channel biologi
Holic Sebelumnya saya ucapkan terima
kasih karena sudah mengklik video ini
pada video kali ini kita akan membahas
mengenai anatomi akar dari penampang
membujur
bagian paling ujung dari akar adalah
tudung akar
tudung akar berfungsi untuk melindungi
sel-sel meristem saat membelah sehingga
dapat menembus tanah tanpa mengalami
kerusakan dan dapat menambatkan tubuh
tumbuhan dengan kuat ke dalam tanah
penyusun tudung akar terbagi menjadi 2
tipe sel yaitu sel kolumnar digambar ini
yang berwarna coklat terdiri dari
sekitar
15-20 amiloplas amiloplas adalah sel
yang mengandung amilum sel columella
berperan sebagai respon terhadap gaya
gravitasi sehingga akar dapat tumbuh ke
bawah tipe yang kedua adalah Sel perifer
digambar ini yang berwarna abu-abu sel
perifer berasal dari sel kulit sayang
berdiferensiasi
terletak di sekeliling columella sel-sel
perifer sebagian besar akan terlepas
dari tudung akar saat akar menembus
tanah Selain itu sel-sel perifer akan
mensekresikan lendir atau musikal ini
lapisan yang melindungi ujung akar
mucigel tersusun atas polisakarida
terhidrasi yang mengandung gula asam
organik vitamin enzim dan asam amino
mucigel berfungsi untuk proteksi atau
perlindungan akar dari kekeringan
lubrikasi atau semacam pelumas bagi akar
sehingga memudahkan akar menembus tanah
Selain itu untuk absorbsi yaitu
Penyerapan air dan garam mineral dari
tanah di belakang tudung akar terdapat
berbagai Zona pertumbuhan primer pada
akar yaitu zona pembelahan sel atau Zona
meristematik zona pemanjangan atau
elongasi
Hai dan zona pematangan
Hai jadi ada tiga Zona pertumbuhan
primer ya Oke kita ke Jona pertumbuhan
primer yang pertama yaitu zona
pembelahan sel zona pembelahan sel
merupakan wilayah dimana terjadi
pembelahan sel secara cepat pada zona
ini terdapat meristem apikal dan
meristem primer perlu kita ketahui bahwa
jaringan meristem merupakan jaringan
yang sel-selnya membelah secara
terus-menerus
meristem apikal menghasilkan sel-sel
meristem dan mengganti tudung akar yang
mengelupas saat menembus tanah di dalam
wilayah meristem apikal terdapat sel
pusat tenang yang berfungsi sebagai
cadangan pemulihan meristem apabila
mengalami kerusakan sel-sel pada pusat
tenang pembelahan selnya berjalan lambat
namun sel-selnya lebih resisten terhadap
radiasi dan zat kimia beracun
meristem primer pada zona pembelahan sel
terdiri dari tiga jenis yaitu
protoderma
meristem dasar
dan Pro cium
protoderma akan berkembang menjadi
epidermis meristem dasar akan berkembang
menjadi jaringan dasar terutama pada
lapisan korteks dan program biung akan
berkembang menjadi silinder pusat atau
stele
selanjutnya zona pemanjangan atau
elongasi Juna elongasi dimulai sekitar
dari 0,5 sampai 1,5 mm dari ujung akar
pada zona ini sel-sel akan memanjang
hingga 10 kali lipat panjang asalnya
ketika sel mengalami pemanjangan maka
Jono meristem matik akan terdorong
kedepan sehingga akar dapat memanjang
kemudian Jono pematangan Jono pematangan
adalah daerah yang sel-selnya mengalami
spesialisasi struktur dan fungsinya
sel-sel pada zona ini sudah sempurna
proses diferensiasinya sehingga
membentuk jaringan yang berbeda-beda
Hai itu tadi mengenai tiga Zona
pertumbuhan primer pada akar
sekarang kita bahas jenis-jenis jaringan
yang ada pada zona-zona tersebut
lapisan terluar dari akar adalah
epidermis
epidermis berasal dari protein pada zona
pembelahan sel-sel epidermis berdinding
tipis
epidermis berperan dalam pembentukan
rambut akar rambut akar merupakan
penjuluran epidermis berfungsi untuk
memperluas daerah permukaan untuk
Penyerapan air dan garam mineral dari
dalam tanah
bagian sebelah dalam epidermis adalah
korteks korteks tersusun atas jaringan
Parenkim yang menyimpan karbohidrat dan
plasma membran nya menyerap air dan
mineral dari rambut akar air dan garam
dari rambut akar akan melewati sel-sel
korteks melalui ruang intracellular
sel-sel korteks yang dilewati air ini
disebut sebagai benang-benang
plasmodesmata
di sebelah dalam korteks adalah
endodermis jika ini yang berwarna
abu-abu
endodermis sel-selnya tersusun rapat
tanpa ruang antar sel sel endodermis
mudah dinding selnya tipis dan bersifat
semipermeabel
sedangkan sel-sel endodermis tua
mengalami penebalan dengan zat gabus
atau suberin membentuk pita kaspari yang
melingkar
endodermis merupakan jaringan yang
mengatur pemasukan air ke dalam jaringan
angkut xilem yang berada didalam
silinder pusat fungsi lainnya adalah
untuk seleksi unsur hara yang akan
diserap oleh tumbuhan dan juga untuk
menyimpan cadangan makanan
selanjutnya stelle atau silinder pusat
yang berkembang dari prokambium pada
stelle terdapat berkas pembuluh yaitu
xilem dan floem
xilem berfungsi untuk mengatur zat hara
yaitu Air dan mineral ke daun adalah
Hai floem berfungsi untuk
mendistribusikan hasil proses
fotosintesis ke seluruh tubuh tumbuhan
Hai xilem pada akar dikotil terletak di
tengah dan berbentuk bintang atau huruf
x floemnya terletak disebelah luar xilem
sementara pada akar monokotil xilem dan
floem nya posisinya berselang-seling dan
melingkar
demikian penjelasan mengenai penampang
membujur akar semoga bermanfaat mohon
maaf jika ada salah sampai jumpa di
video video selanjutnya terima kasih
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