RE 9.3 DNA, Asexual Reproduction, Mitosis, Sexual reproduction, and Meiosis

Question 1

Define the following word; Biology

Answer 1

The study of living organisms and their interactions with the environment. includes plants, animals, fungus, and microorganisms

Question 2

Answer the questions - All different subtopics of biology

Answer 2

Cell Biology, Biochemistry, Zoology, Botany

Question 3

Biological definition of; life, biotic, and abiotic

Answer 3

life; What distinguishes living organism from non-living matter, involving processes like growth, reproduction, and response to the environment.
biotic; something that is living or was once living
abiotic; something that was never living

Question 4

Answer the question - All living do what?

Answer 4

• All living things are made of cells
• Reproduce by passing DNA on to offspring
• Uses energy
• Have some sort of motion
• All living things grow and develop
• Living things can adopt and evolve

Question 5

Answer the question - Cell Theory

Answer 5

• All living things are composed of cell
• Cells are the basic unit of Ife
• Cells are usually microscopic

Question 6

Answer the question - what is DNA and what does it stand for

Answer 6

DNA stands for Deoxyribonucleic Acid. DNA is the genetic material of living things, it contains the genetic instructions for cells and determines their functions. When an organism reproduces, it passes a portion of its DNA to its offspring.

Question 7

Answer the question - How many DNA different strands are there, and what connects the middle.

Answer 7

DNA molecules is made of 2 different strands connected together, and are connected in the middle with nitrogenous bases.

Question 8

Answer the question - How many bases are there, what do they stand for and what base links together?

Answer 8

There are 4 bases, these are known as nitrogenous bases
- Adenine (A) (A) on one strand always connects to (T) on the other strand
- Thymine (T)
- Cytosine (C) (C) on one strand always connects to (G) on the other strand
- Guanine (G)

Question 9

Answer the question - What do bases determine?

Answer 9

The bases determine what is known as our genes

Question 10

Define the following word; Gene

Answer 10

Simple definition; Areas on our DNA that determine different traits, genes make up much of who we are
Definition; Genes are like instructions in DNA that determine traits and how living things work.

Question 11

Answer the question - What is a Nucleotides

Answer 11

Nucleotides hook together to make strands. The phosphates always connect to the sugars. This makes a DNA strand

Question 12

Answer the question - What is the structure of a DNA

Answer 12

shorten definition; DNA, a 3D complex structure has a twisted and coiled ladder-like structure called a double helix.

Question 13

Answer the question - What is DNA sequence

Answer 13

The order the nitrogenous bases are attached, it’s were DNA stores it’s information and this sequence determines how cell function

Question 14

Answer the question - How does DNA sequences determine the function of you cells

Answer 14

The sequence is used to make proteins, these proteins carry out all the functions of the cell.

Question 15

Answer the question - How does DNA make proteins?

Answer 15

In every 3 nucleotides, it tells the cell what amino acid to use, these amino acids hook to each other. DNA will eventually tell the cell to stop adding amino acids. This section of the DNA that makes 1 protein is called a gene.

Question 16

Answer the question - What is DNA replication

Answer 16

DNA is self-replicating, meaning it can copy of itself. DNA copies itself when a cell needs to make a copy of itself.

Question 17

Define the following word Reproduction,

Answer 17

When one or more organism produce a new organisms.

Question 18

Define the following word; Parent and offspring

Answer 18

the pre-existing organism is called the parent, the new organisms is called the offspring

Question 19

Define the following word; Asexual Reproduction

Answer 19

The offspring produced has the exact same DNA as the parent, this mean the offspring is exactly the same as the parent
- Requires one parent
- Exact same genes as the parent
- Only way for variation is by mutation

Question 20

Define the following word; Sexual Reproduction

Answer 20

The offspring receives half of it’s DNA from a female and half it’s DNA from the male. This produces an organism with a completely different DNA code.
- Requires two parents
- Parents divide their genetic material and gives half of their genes to the offspring
- offspring gets half of it’s genes from one parent and the other half from the other parent
- means more variation as every offspring has a new genetic doe.

Question 21

Answer the question: What are the advantages of asexual reproduction?

Answer 21

Offers efficiency, rapid population growth, and genetic consistency. It doesn’t require finding a mate, enabling quick multiplication of genetically identical offspring, which is advantageous in stable environments.

Question 22

Answer the question: What are the advantages of sexual reproduction?

Answer 22

Sexual reproduction offers genetic diversity, adaptation to changing environments, and the ability to remove harmful mutations through recombination, promoting the survival and evolution of species.

Question 23

How do spindle fibers connect and detach during cell division?

Answer 23

Spindle fibers attach to chromosomes via kinetochores during cell division, ensuring proper alignment. Enzymes break down these connections during anaphase, allowing chromosomes to separate and move to opposite poles, ensuring genetic fidelity in daughter cells

Question 24

Define the following words; Diploids and Haploids

Answer 24

Haploids; are cells or organisms that have only one set of chromosomes, rather than the usual two sets found in diploid cells.
Diploids; Diploids are cells or organisms that contain two sets of chromosomes, typically one set from each parent, resulting in pairs of homologous chromosomes.

Question 25

Why do sex cells only contain half of an organism’s genes?

Answer 25

Sex cells, like sperm and egg cells, contain only half of an organism’s genes because during meiosis, chromosomes are halved to ensure that when they combine during fertilization, the offspring have the right number of chromosomes.

Question 26

Answer the question: Why do duplicated cells only have half of the DNA?

Answer 26

Duplicated cells have half the DNA because during cell division, specifically during meiosis, the chromosomes are halved to ensure the resulting cells have the correct number of chromosomes, contributing to genetic diversity and ensuring proper inheritance.

Question 27

Define the following word: Meiosis.

Answer 27

Meiosis is a special type of cell division that creates sex cells like sperm and egg cells, each having half the number of chromosomes of the parent cell, important for reproduction and genetic variety.

Question 28

Answer the following word; What are the process of Meiosis

Answer 28

Answer: Meiosis is a type of cell division that consists of two main stages: Meiosis I and Meiosis II. The stages of meiosis are: Prophase I, Metaphase I, Anaphase I, Telophase I, Cytokinesis I, Prophase II, Metaphase II, Anaphase II, Telophase II, and Cytokinesis II.

Question 29

Answer the question; What happens in Prophase I and Metaphase I

Answer 29

Prophase I:
During Prophase I, chromosomes condense and become visible. Homologous pairs align closely and exchange genetic material through a process called crossing over, which increases genetic diversity among the resulting daughter cells.

Metaphase I:
In Metaphase I, the paired homologous chromosomes line up along the cell’s equator, with spindle fibers attaching to each chromosome. The orientation of the pairs is random, contributing to genetic variation in the daughter cells.

Question 30

Answer the following question; What happens in Anaphase I and Telophase I/Cytokinesis I

Answer 30

Anaphase I:
During Anaphase I, the homologous chromosomes separate and move to opposite poles of the cell, pulled by the spindle fibers. This ensures that each daughter cell receives one chromosome from each homologous pair.

Telophase I/Cytokinesis I:
Telophase I marks the end of the first division of meiosis. Chromosomes reach the poles, and nuclear envelopes reform around them. The cell then undergoes cytokinesis, dividing into two daughter cells, each with half the original chromosome number.

Question 31

Answer the question; What happens in Prophase II and Metaphase II

Answer 31

Prophase II:
During Prophase II, a brief phase, the nuclear envelope dissolves again, and a new spindle apparatus forms in each daughter cell.

Metaphase II:
In Metaphase II, chromosomes align individually along the equator of each daughter cell, attached to spindle fibers.

Question 32

Answer the question; What happens in Anaphase II and Telophase II/Cytokinesis II

Answer 32

Anaphase II:
During Anaphase II, sister chromatids separate and move toward opposite poles of the cell, guided by spindle fibers.

Telophase II/Cytokinesis II:
Telophase II sees the arrival of chromosomes at opposite poles, where new nuclear envelopes form. The cell then undergoes cytokinesis, dividing into four haploid daughter cells, each containing a unique combination of genetic material.

Question 33

Define the following word; Mitosis

Answer 33

Mitosis is a process of cell division in which a single cell divides into two daughter cells, each having the same number and kind of chromosomes as the parent cell. It plays a crucial role in growth, development, and tissue repair in multicellular organisms.

Question 34

List all the stages of; Mitosis

Answer 34

The stages of mitosis are Prophase, Metaphase, Anaphase, Telophase, and Cytokinesis.

Question 35

Answer the following question; explain the mitosis stages of Prophase and Metaphse

Answer 35

Prophase:
Chromosomes condense, the nuclear envelope breaks down, and spindle fibers form, preparing for chromosome movement.

Metaphase:
Chromosomes line up along the cell’s equator, attached to spindle fibers, ensuring proper distribution.

Question 36

Answer the question; Explain the stages of Anaphase, Telophase, and Cytokinesis

Answer 36

Anaphase:
Sister chromatids separate and move to opposite poles of the cell, pulled by spindle fibers, ensuring each daughter cell receives a full set of chromosomes.

Telophase:
Chromosomes reach poles, nuclear envelopes form around them, and chromosomes unwind, preparing for cytokinesis.

Cytokinesis:
The cell divides into two daughter cells, each containing a complete set of chromosomes, ensuring proper genetic inheritance.

Question 37

Answer the question: Why is it important to have genetic variation?

Answer 37

Genetic variation is important because it increases a population’s ability to adapt to changing environments, improves chances of survival against diseases, and contributes to the overall health and resilience of a species.