Prokaryotes, Eukaryotes, Genes, and Chromosomes Flashcards
condensed, visible, and inactive form of chromatin
heterochromatin
less coiled, lightly stained, diffused, and active form of chromatin
euchromatin
product of gene expression
(often) proteins
process by which information of a gene is used in the synthesis of a functional gene product
gene expression
study of mechanisms that lead to changes in gene expression that can be passed from cell to cell and are reversible, but do not involve a change in the sequence of DNA
epigenetics
gene expression vary according to:
[CST]
(1) conditions around the cell
(2) signals received at the cell surface membrane
(3) specific cell type (determined during development of embryo)
process that makes the function and morphology of each cell unique
gene expression
true or false. gene expression patterns change over time and in different cell types
true
2 general processes of gene expression:
chromatin remodelling and small RNAs (micro RNAs)
in chromatin remodelling, acetyl and phosphate group turn on _____________, while ______ group turns off transcription
in chromatin remodelling, acetyl and phosphate group turn on transcription, while methyl group turns off transcription
small RNAs bind to the __ ends of certain mRNAs
3’
small RNAs prevent the ___________ of mRNAs into proteins
translation
exceptions to gene expression:
[MSEB]
(1) mature RBCs: contain no DNA
(2) sperm and egg: have half the amount of DNA
(3) B cells: some DNA have been rearranged to form antibodies
types of heterochromatin:
[KMN - Kill Me Now]
(1) karyosome
(2) marginal chromatin
(3) nucleolar-associated chromatin
small piece of DNA that codes for a specific trait
gene
DNA is wound around positively charged proteins called ________
histones
arrange the steps:
(a) chromatin fibre condense
(b) DNA wraps around histones, forming nucleosomes
(c) condensed chromatin forms a chromosome
(d) nucleosomes condense into a chromatin fibre
B, D, A, C
coiled DNA strands to basic proteins called histones
chromatin
chromatin that has undergone further condensation
chromosome
true or false. chromatin is present in actively dividing cells
false. chromatin is only present in metabolically active cells
chromosomes are the ones present in actively dividing cells
chromosomes were discovered by __ and the term was coined by __
(a) C. Von Nageli
(b) W. Waldeyer
A, B
Nageli sounds lyk Magellan who discovered PH so he discovered chromo xd
DNA + PROTEIN =
CHROMATIN
true or false. all eukaryotes have chromosomes in the interface between cell divisions, but they are diffused throughout the nucleus, and usually unidentifiable
true
tightly packed DNA that is found only during cell division, and not used for macromolecule synthesis
chromosome
unwound DNA that is found throughout interphase, and used for macromolecule synthesis
chromatin
chromosomes are arranged from:
(a) largest to smallest
(b) smallest to largest
(a) largest to smallest
alterations and abnormalities in chromosomes can be identified through the _________
karyotype
how many pairs of chromosomes are present when the egg cell and sperm cell meet?
23 pairs
the first 22 pairs of chromosomes are called
autosomes
morphologically identical members of a homologous pair of chromosomes
homomorphic chromosome pairs
the last pair of chromosomes (XX and XY) are called
sex chromosomes
a sperm and an egg cell, each containing 23 chromosomes, can form 1 human being. when these chromosomes divide, how many chromosomes will there be?
92
_ arm: short arm
_ arm: long arm
p arm: short arm
q arm: long arm
end of the chromosome
telomere
constriction and attachment point of chromatids
centromere
in females (XX), one X chromosome is tightly coiled and visible while the other is uncoiled
in males (XY), the X chromosome is _______
uncoiled
it is a small densely staining structure in the cell nuclei of female mammals
barr body
the barr body consists of a condensed inactive X chromosome, regarded as
genetic femaleness
also known as body cells, it is any cell of a living organism other than the reproductive cells
somatic cells
cell containing half the number of chromosomes of a somatic cell
germ cell
somatic cells have ___ copy/ies of the genome, and are said to be _______
2, diploid
germ cells contain ___ copy/ies of the genome are said to be _______
1, haploid
these cells are able to unite with one of the opposite sex to form a new individual
germ cells
in the diploid state, members of the same chromosomes are referred to as
homologous chromosomes
this shows the total chromosomal complement of a cell
karyotype
in karyotype, chromosomes are photographed during which process?
mitosis
centromere, where two sister chromatids attach, contains a portion where mitotic spindles will attach to. this is termed as
kinetochore
centromere is in the middle, and the arms are of equal length
metacentric
centromere is between the midpoint and one end
submetacentric
centromere is near one end
acrocentric
centromere is at the end
telocentric
this structure protects the chromosomes during cell division from deterioration, and shortens every cell division
telomere
