Year 10 Semester 2 Term 3

Question 1

What does the nucleus hold?

Answer 1

The nucleus holds all DNA and genetic information.

Question 2

What is the nucleus?

Answer 2

The nucleus is enclosed by a nuclear membrane and controls cell activity - specifically protein production.

Question 3

What does DNA stand for?

Answer 3

Deoxyribose Nucleic Acid

Question 4

What is DNA?

Answer 4

A molecule that carries genetic instructions for all organisms’ development, functioning, growth, and reproduction.

Question 5

What does DNA control?

Answer 5

DNA controls all chemical changes in cells.

Question 6

What does DNA do?

Answer 6

DNA controls the kind of organism produced.

Question 7

What is a DNA molecule?

Answer 7

DNA is a large molecule made of a chain of nucleotides. Each nucleotide consists of a sugar, phosphate group, and a nitrogenous base pair.

Question 8

What are the most common organic bases?

Answer 8

Adenine, Thymine, Cytosine, and Guanine.

Question 9

Describe the DNA structure

Answer 9

DNA is like a twisted ladder, with the phosphate and sugar in a nucleotide forming the sides of the DNA ladder, known as the sugar-phosphate backbone. Strong covalent bonds connect the sugar of one nucleotide to the phosphate of the next, and the paired strands are coiled into a double helix.

Question 10

Define Gene

Answer 10

A section of DNA on a chromosome that contains the information for a protein or RNA, and codes for trials.

Question 11

Define Chromosomes

Answer 11

When a cell is getting ready to divide, the DNA molecule is packed into thread-like structures called chromatin inside the nucleus..

Question 12

What are chromosomes made up of?

Answer 12

Each chromosome is made up of DNA lightly coiled around proteins called histones.

Question 13

What do Histone proteins do?

Answer 13

Histone proteins help DNA coil up and form its shape, found in the nucleus.

Question 14

What is a Chromatid?

Answer 14

Two exact copies of a chromosome that are connected together.

Question 15

What is a centrometre?

Answer 15

The point where chromatids are connected.

Question 16

When are Chromatids made?

Answer 16

Made when new cells are going to be made.

Question 17

When are Chromosomes visible?

Answer 17

When a cell is dividing, usually seen in the double-stranded form.

Question 18

What is a Homologous Pair of Chromosomes?

Answer 18

Chromosomes contain the same type of genetic information. One comes from male parents, the other from the female parent.

Question 19

What is a karyotype?

Answer 19

The general appearance of the complete set of chromosomes in the cells of a species.

Question 20

What are the types of chromosomes?

Answer 20

Autosomes and sex chromosomes.

Question 21

What are autosomes?

Answer 21

Body chromosomes or non-sex chromosomes ( humans have 44 or 22 pairs)

Question 22

What are sex chromosomes?

Answer 22

The 23rd pair of chromosomes that determine the sex of the individual.

Question 23

What are autosomal chromosomes?

Answer 23

The first 22 pairs of homologous chromosomes.

Question 24

Where do we find DNA in eukaryotic cells?

Answer 24

In the nucleus

Question 25

What kind of bonds hold the base pair together?

Answer 25

Hydrogen bonds

Question 26

What is a somatic cell?

Answer 26

All cells in the body, except for germ cells

Question 27

What is a germ cell?

Answer 27

Contain half the number of chromosomes, only found in the ovaries and testes - reproductive organs.

Question 28

What is mitosis?

Answer 28

When a cell divides its DNA and cytoplasm, forming two new cells.

Question 29

What are the phases of Mitosis?

Answer 29

PMAT

Question 30

What is prophase?

Answer 30

Chromosomes condense and become visible, the nucleus disintegrates, and the mitotic spindle begins to form.

Question 31

What is metaphase?

Answer 31

Chromosomes line up in the middle of the cell and spindle fibres attach to the centrometre.

Question 32

What is Anophase?

Answer 32

Sister chromatids pull apart to opposite poles of the cell.

Question 33

What is telophase?

Answer 33

Two chromatids/chromosomes move to opposite ends of the cell and 2 nuclei form.

Question 34

What is Meiosis?

Answer 34

A special process of nuclear division that results in the production of sperm or eggs.

Question 35

What is chromatin?

Answer 35

A combination of DNA and protein found in eukaryotic cells

Question 36

What are sister chromatids?

Answer 36

Two identical copies of a chromatid

Question 37

What is a centrometre?

Answer 37

A structure in a chromosome that keeps the two characteristic chromatids together.

Question 38

What are spindle fibres?

Answer 38

Controls the movement and separation of chromosomes during cell division.

Question 39

What do centrioles do?

Answer 39

Help in the formation of spindle fibres.

Question 40

What is a nuclear envelope?

Answer 40

A membrane that separates the nucleus from the cytoplasm in eukaryotic cells.

Question 41

What happens during interphase?

Answer 41

Cell growth, DNA synthesis, and Preparation for Mitosis. The cells grow, and replicate DNA and organelles.

Question 42

Why is mitosis important?

Answer 42

Vital for the growth, development, repair, and maintenance of living organisms.

Question 43

How many chromosomes do daughter cells have?

Answer 43

Contains 23 chromosomes known as a haploid. Avoids doubling the amount of DNA every time fertilisation occurs.

Question 44

What are the main stages of Meiosis?

Answer 44

Meiosis 1 and Meiosis 2

Question 45

What is meiosis 1?

Answer 45

Homologous chromosomes separate and create 2 daughter nuclei

Question 46

What is meiosis 2?

Answer 46

2 daughter nuclei divide, sister chromosomes are separated to create 4 gametes.

Question 47

What are gametes?

Answer 47

An organisms' reproductive cells, also referred to as sex cells.

Question 48

What happens in interphase during Meiosis

Answer 48

DNA replication and the cell enters the reproductive cycle with 4 copies of each chromosome.

Question 49

What happens in Prophase 1 during Meiosis 1?

Answer 49

Chromosomes pair up in homologous pairs, and crossing over occurs. DNA condenses around histones. Nuclear membrane breaks down.

Question 50

What happens in Metaphase 1 during Meiosis 1?

Answer 50

Homologous pairs align in the middle. Random assortment takes place.

Question 51

What happens in Anophase 1 during Meiosis 1?

Answer 51

Homologous chromosomes attach to spindles and separate to opposite sides/poles of the cell.

Question 52

What happens in Telophase 1 during Meiosis 1?

Answer 52

Nuclear membrane reform, chromosomes disperse followed by cytokinesis.

Question 53

What is Cytokinesis during Meiosis 1?

Answer 53

Division of cytoplasm occurs, there may be a short pause.

Question 54

What happens in Prophase 2 during Meiosis 2?

Answer 54

Chromosomes condense, the nuclear envelope dissolves, and centrioles migrate.

Question 55

What happens in Metaphase 2 during Meiosis 2?

Answer 55

Chromosomes align in the middle and spindles form.

Question 56

What happens in Anophase 2 during Meiosis 2?

Answer 56

Sister chromatids separate and spindles contract.

Question 57

What happens in Telophase 2 during Meiosis 2?

Answer 57

Nuclear membranes reform, followed by cytokinesis, resulting in 4 non-identical daughter cells.

Question 58

What does Mitosis create?

Answer 58

All somatic cells in the body.

Question 58

What happens in Cytokinesis 2 during Meiosis 2?

Answer 58

Division of cytoplasm, four haploid daughter cells are produced and each cell is genetically different.

Question 59

What does Meiosis create?

Answer 59

Gametes.

Question 60

What are the similarities between mitosis and meiosis?

Answer 60

- Starts with a diploid cell. - DNA replication occurs. - Makes new cells

Question 61

What is meant by crossing over of Chromosomes?

Answer 61

Swapping over genetic material between homologous chromosomes during meiosis.