Chromosomes And Meiosis

Question 1

Chromosomes

Answer 1

Long, thread-like structures that form part of the chromatin network in the nuclei of cells
- can be stained easily

Question 2

Somatic cells

Answer 2

Body cells

Question 3

Homologous pair

Answer 3

Matching maternal and paternal chromosomes (same size, shape and coding genes in place)

Question 4

Chromatids

Answer 4

2 identical threads formed during chromosome replication

Question 5

Diploid

Answer 5

2n

Cells containing full number of chromosome (e.g. 46 in humans)

Question 6

Allele

Answer 6

One or two more forms of a gene

- a contrasting form of a gene for the same characteristic

Question 7

Meiosis

Answer 7

Cell division that takes place in reproductive organs of both plants and animals to produce gametes (sex cells) in animals and spores in plants

Question 8

Haploid

Answer 8

n

Cells that have half the number of chromosomes

Question 9

Gene

Answer 9

A short length of DNA which controls and organisms characteristic
- sections of chromosome that code for specific characteristics

Question 10

Morula

Answer 10

Basic mass of replicated cells which form basic embryo

Question 11

Microsporangia

Answer 11

Pollen sacs in the male anthers (part of stamen)

Question 12

Mega sporangia

Answer 12

Ovules in the female ovaries

Question 13

Meiosis 1

Answer 13

Reduction division

- results in two cells being formed- each with a haploid (n) number

Question 14

Meiosis 2

Answer 14

Copying division

- involves two haploid cells replicating to form 4 haploid cells

Question 15

Chiasma

Answer 15

Point of contact and where breakage occurs between two chromatids

Question 16

Synapsis

Answer 16

Process in which replicated homologous pairs come together to form bivalents

Question 17

Bivalent

Answer 17

Chromosomes which lie next to each other

Question 18

Tetrad

Answer 18

2 chromosomes that make up a homologous pair

Question 19

Genome

Answer 19

All the genes in an organism

Question 20

Chromosomal non-disjunction

Answer 20

Occurs when chromosomes fail to separate correctly during Anaphase 1 of meiosis

Question 21

Aneuploidy

Answer 21

Condition resulting from fertilization involving abnormal gametes which result in a zygote with an extra/ missing chromosome

Question 22

Syndrome

Answer 22

Physical/ mental characteristics affected individuals suffer from

Question 23

Diagnosis

Answer 23

Identifying the nature of an event

Question 24

Prognosis

Answer 24

Predicting how the event will develop

Question 25

Amniocentesis

Answer 25

Process whereby a small sample of fluid is removed from the amniotic cavity in the uterus

Question 26

Polyploidy

Answer 26

A condition where there are more than two sets of chromosomes in a cell.
Occurs more commonly in plants
Occurs as a result of abnormal mitosis where a full set of chromosomes does not separate during Anaphase 1

Question 27

Total non-disjunction

Answer 27

The phenomenon there a full set of chromosomes does not separate during meiosis

Question 28

Autosome

Answer 28

The normal chromosomes not involved in sex determination

Question 29

Gonosome

Answer 29

The sex chromosomes that determine the gender of an individual

Question 30

Karyotype

Answer 30

The complete number of chromosomes in a diploid cell, arranged in Paris according to size, shape and number