Unit 1: Mitosis, Meiosis, and cell specialisation

Question 1

What is an allele?

Answer 1

A version of a gene.

Question 2

What is asexual reproduction?

Answer 2

The production of genetically identical new organisms by a single ‘parent’ organism.

Question 3

What is a chromatid?

Answer 3

A replicated chromosome appears as two identical strands in early stages of cell division. Each strand is a chromatid.

Question 4

What is chromatin?

Answer 4

Material staining dark red in the nucleus during interphase of mitosis and meiosis. It consists of nucleic acids and proteins. Chromatin condenses into chromosomes during prophase of nuclear division.

Question 5

What is a chromosome?

Answer 5

A linear DNA molecule wrapped around histone proteins found in the nucleus. Chromosomes become visible in prophase of nuclear division.

Question 6

What is artificial selection?

Answer 6

(selective breeding) the process of improving a variety of crop plant or domesticated animal by breeding from selected individuals with desired characteristics.

Question 7

What are ciliated epithelium?

Answer 7

Epithelial cells that have cilia on their cell surface.

Question 8

What are clones?

Answer 8

Genetically identical cells or individuals.

Question 9

What is cytokinesis?

Answer 9

The division of the cell, following nuclear division, to form two new cells.

Question 10

What is differentiation?

Answer 10

The development and changes seen in cells as they mature to form to form specialised cells.

Question 11

What does diploid mean?

Answer 11

Cells or organisms that have two copies of each chromosome in their nuclei.

Question 12

What is Endothelium?

Answer 12

A tissue that lines the inside of a structure, such as a blood vessel.

Question 13

What is the Epidermis?

Answer 13

Outer layer(s) of cells of a multicellular organism. Plants have a single layer surrounding the tissues of roots, stems and leaves. Invertebrates have an epidermis made of a single layer of cells that secrete a cuticle, Vertebrate (including mammals) epidermis consists of several layers, the outer layer being made of dead cells.

Question 14

What is epithelium?

Answer 14

A tissue that covers the outside of a structure.

Question 15

What are Erythrocytes?

Answer 15

Red blood cells.

Question 16

What is a gamete?

Answer 16

Sex cells, usually haploid (one set of chromosomes). Male and female gametes can fuse, during sexual reproduction, to form zygotes (diploid).

Question 17

What is a gene?

Answer 17

A length of DNA that carries the code for the synthesis of one or more specific polypeptides.

Question 18

What is a gene pool?

Answer 18

The sum total and variety of all the genes in a population or species at a given time.

Question 19

What is genome?

Answer 19

All the genetic material inside an organism (or cell).

Question 20

What does haploid mean?

Answer 20

A cell or organism that has one set of chromosomes/one copy of each chromosome.

Question 21

What does histone mean?

Answer 21

Type of protein association with DNA in eukaryotes. DNA is wound around histone proteins to form chromatin.

Question 22

What does homologous mean?

Answer 22

Chromosomes that have the same genes at the same loci. Members of an homologous pair of chromosomes pair up during meiosis.

Question 23

What is interphase?

Answer 23

The phase of the cell cycle where synthesis of new DNA and organelles takes place.

Question 24

What is meiosis?

Answer 24

Nuclear division that results in the formation of cells containing half the number of chromosomes of the adult cell.

Question 25

What is metaphase?

Answer 25

The phase of mitosis where the chromosomes line up at the equator of the spindle.

Question 26

What is Mitosis?

Answer 26

Nuclear division that results in the formation of cells that are genetically identical to the parent cell.

Question 27

What are neutrophils?

Answer 27

Phagocytic white blood cells. They engulf and digest bacteria. Neutrophils have a many-lobed nucleus, and a granular cytoplasm due to the large numbers of lysosomes present.

Question 28

What is an organ?

Answer 28

A collection of tissues that work together to perform a specific overall function or set of functions within a multicellular organism.

Question 29

What does pluripotent mean?

Answer 29

Stem cells capable of differentiating to become a limited number of cell types found in the organism.

Question 30

What are root hair cells?

Answer 30

Cells in the epithelium of roots that have long extensions to increase surface area for the absorption of water and minerals.

Question 31

What are stem cells?

Answer 31

Undifferentiated cells that are capable of becoming differentiated to a number of possible cell types.

Question 32

What is telephase?

Answer 32

Final phase of mitosis. Two new nuclear envelopes form around the two new nuclei.

Question 33

What is a tissue?

Answer 33

A group of similar cells that perform a particular function.

Question 34

What does totipotent mean?

Answer 34

Undifferentiated cell that is capable of differentiating into any kind of specialised cell. All cells in an embryo are totipotent, as are meristem cells in plants.

Question 35

What is a zygote?

Answer 35

Diploid cell made from fusion of male and female gametes.