Grade 9 Biology Reinforcement Worksheet: Cell, Tissues, Reproduction, How Life Continues

Practice flashcards covering key concepts, questions, and answers from the Grade 9 Biology reinforcement worksheet on Cells, Tissues, Reproduction, and How Life Continues.

What happens to a cell when it is placed in a hypotonic solution?

It gains water and swells.

Which organelle is primarily responsible for modifying, packaging, and transporting materials within the cell?

Golgi apparatus

Which plant tissue provides flexibility to parts such as young stems and leaf stalks?

Collenchyma

Which plant tissue is responsible for the transport of water and minerals from roots to other parts of a plant?

Xylem

What is an example of asexual reproduction mentioned in the worksheet?

Binary fission in Amoeba

Where is the genetic material of a cell primarily located?

Nucleus

Why is sexual reproduction important in the continuity of life?

It introduces variations among offspring.

Why do plant cells not burst easily when placed in a hypotonic solution?

The rigid cell wall provides resistance against excessive expansion of the cell.

How do meristematic tissues help plants increase in length and girth?

Meristematic cells actively divide to produce new cells.

Why is the plasma membrane described as selectively permeable?

It allows some substances (such as water, oxygen, and carbon dioxide) to pass through while restricting others.

How does the selective permeability of the plasma membrane benefit the cell?

It allows the cell to take in needed substances, remove wastes, and keep its internal environment stable.

How do meristematic tissue and permanent tissue differ in their ability to divide?

Meristematic cells divide actively, whereas permanent tissue cells have lost the ability to divide.

How do meristematic cells and permanent tissue cells differ in their size and nature?

Meristematic cells are small and thin-walled with dense cytoplasm, a prominent nucleus, and few or no vacuoles; permanent tissue cells are larger, have a definite shape and function, may have large vacuoles, and may be living or dead.

What is fertilisation?

The fusion of a male gamete and a female gamete to form a zygote.

Why is fertilisation important in sexual reproduction?

It combines genetic material from two parents, producing variation, and forms a zygote that develops into a new organism.

If Cell A has a cell wall, chloroplasts, and a large vacuole, while Cell B lacks a cell wall and chloroplasts, how are these cells identified?

Cell A is a plant cell and Cell B is an animal cell.

State two structural differences between plant cells and animal cells.

Plant cells possess a cell wall, chloroplasts/plastids, and a large central vacuole, whereas animal cells lack a cell wall and chloroplasts, have small or no vacuoles, and contain centrioles.

How does the production of offspring contribute to the continuity of life?

Offspring replace individuals that die, allowing populations to continue.

How does the transmission of genetic information ensure the continuity of life?

DNA is copied and passed to offspring so that they resemble their parents and keep the same body design.

How does variation contribute to the continuity of life?

Variation arising from DNA copying and sexual reproduction helps some individuals survive environmental changes, ensuring the species continues.

What type of plant tissue consists of actively dividing cells at the growing tip of a plant?

Apical meristem (meristematic tissue)

What type of plant tissue consists of elongated cells with uneven thickening at the corners?

Collenchyma

What type of plant tissue consists of dead cells with thick, lignified walls, and what is its function?

Sclerenchyma; it provides strength and rigidity to plant parts, such as the husk of coconut, stems, and veins of leaves.

What is the basic structural and functional unit of life?

Cell

What is the function of mitochondria in a cell?

They serve as the site of cellular respiration, releasing energy in the form of ATP (powerhouse of the cell).

How do cells become specialised to form different tissues?

Through differentiation, where cells take up a permanent shape, size, and function, and usually lose the ability to divide.

Compare plant tissues and animal tissues with respect to their major functions and characteristics.

Plants are stationary, so many of their tissues are supportive and dead (such as sclerenchyma) with growth limited to meristems; animals move, so most of their tissues are living, use more energy, and exhibit more uniform growth.