Biology-Cell division and stem cells

Question 1

How is DNA found in eukaryotic organisms

Answer 1

In long strands

Question 2

Purpose

Gene

Answer 2

A code to build a specific protein

Question 3

True or Fasle

Every cell of a multicelluar organsim must contain a full set of DNA,chromsones and genes

Answer 3

True

Question 4

A code to build a specific protein

Answer 4

Purpose

Gene

Question 5

How are new body cells produced

Answer 5

Through Mitosis

Question 6

Define

Interpharse

Answer 6

The pharse in which the cell prepares for division.

Question 7

Define

G1 phase (Gap 1)

Answer 7

The pharse in which the cell grows and performs normal functions.

Question 8

Define

S phase (Synthesis)

Answer 8

The pharse in which DNA replication occurs, doubling the genetic material.

Question 9

Define

G2 phase (Gap 2)

Answer 9

In this pharse the cell continues to grow and prepares for division by producing proteins and organelles.

Question 10

Define

Mitotic Phase (M phase)

Answer 10

The stage in which the cell undergoes division

Question 11

Define

Cytokinesis

Answer 11

When the cytoplasm divides, resulting in two genetically identical daughter cells.

Question 12

Examples

Rapidly Dividing Cells

RDCs

Answer 12

Cells like those in the skin, hair follicles, or the lining of the gut

have short cycles because they need to regenerate quickly to replace damaged or old cells.

Question 13

Examples

Slowly Dividing Cells

SDCs

Answer 13

Liver cells(slowest cells in the body)

sometimes months, to complete the cycle since they don’t need frequent replacement.

Question 14

Examples

Non-Dividing Cells

NDCs

Answer 14

Some cells, like neurons in the brain or cardiac muscle cells

remain in a resting state called G0 phase. These cells rarely, if ever, divide after maturity.

Question 15

List

Mitosis

Answer 15

1. Prophase: The chromatin condenses into visible chromosomes, each consisting of two sister chromatids joined at a centromere. The nuclear envelope begins to break down, and the mitotic spindle (made of microtubules) forms.
2. Metaphase: The chromosomes align along the cell’s equatorial plane, also known as the metaphase plate. The spindle fibers attach to the centromeres of the chromosomes, ensuring proper alignment.
3. Anaphase: The sister chromatids are pulled apart as the spindle fibers shorten. Each chromatid, now an individual chromosome, moves toward opposite poles of the cell.
4. Telophase: The chromosomes reach the poles, and a new nuclear envelope forms around each set, creating two nuclei. The chromosomes begin to decondense back into chromatin.

Question 16

Define

Prophase

Answer 16

When the chromatin condenses into visible chromosomes, each consisting of two sister chromatids joined at a centromere. The nuclear envelope begins to break down, and the mitotic spindle (made of microtubules) forms.

The nuclear envelope begins to break down, and the mitotic spindle (made of microtubules) forms.

Question 17

Define

Metaphase

Answer 17

When the chromosomes align along the cell’s equatorial plane, also known as the metaphase plate.

The spindle fibers attach to the centromeres of the chromosomes,

This ensures proper alignment.

Question 18

Define

Anaphase

Answer 18

When the sister chromatids are pulled apart as the spindle fibers shorten.

Each chromatid moves toward opposite poles of the cell

The chromatids are now individuals chromosomes

Question 19

Define

Telophase

Answer 19

When the chromosomes reach the poles, and a new nuclear envelope forms around each set, creating two nuclei.

The chromosomes begin to decondense back into chromatin.

Question 20

Define

Zygote

Answer 20

A zygote is a fertilized egg

Question 21

Define

Embryo

Answer 21

Ball of stem cells in uterus after fertiliasation

Question 22

True or Fasle

Plants do not possess stem cell

Answer 22

Fasle

Question 23

Location

Plant stem cells

Answer 23

Meristem regions such as the shoots,roots and the stem

Question 24

List

Methods of plant cloning

Answer 24

• Cuttings: A simple and widely used method. A part of the plant, like a stem, leaf, or root, is cut and placed in soil or water to grow roots and develop into a new plant.
• Layering: In this method, a branch or stem is bent to the ground and covered with soil while still attached to the parent plant. Once it develops roots, it can be separated to grow as an independent plant.
• Grafting: A part of one plant (the scion) is attached to another plant (the rootstock). This is often used for fruit trees and roses to combine desirable traits like disease resistance or better yield.
• Micropropagation: A high-tech laboratory method where plant cells or tissues are cultured in a nutrient medium under sterile conditions to grow new plants. It’s great for mass-producing plants.
• Bulbs and Tubers: Some plants, like potatoes or tulips, naturally produce bulbs or tubers that can be separated and replanted to grow clones.

Question 25

Why are pan

Answer 25

* The main reason to clone plants is to mass produce organisms with desired qualities * They aslo can be sold for a hhigh commericial value