Brainscape's Knowledge GenomeTM

Browse over 1 million classes created by top students, professors, publishers, and experts.


See full index

Genetics > DELAYED CHROMOSOMAL AND EXTRACHROMOSOMAL INHERITANCE > Flashcards

DELAYED CHROMOSOMAL AND EXTRACHROMOSOMAL INHERITANCE Flashcards

You may prefer our related Brainscape-certified flashcards:
Biology 101 flashcards
1
Q

Characteristics showing delayed inheritance still conform with the principles of chromosomal genetics but are sidetracked by the ties of the parent.

A

Delayed Chromosomal Inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

The ties are usually between the maternal parent and the offspring. In some cases, maternal influence does not diminish during the development but lasts throughout adult life.

A

Delayed Chromosomal Inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Such maternal inheritance results from 2 important features of the egg but not the sperm
 The orientation of the mitotic spindle axis
 The high cytoplasmic continuity between the egg and the oocyte with very little or no contribution from the sperm.

A

Delayed Chromosomal Inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

In some cases, maternal influence does not diminish during the development but lasts throughout adult life.

  • This occurs when development is started in a specific direction that cannot be reversed.
  • An example is the inheritance of the direction of coiling of the snail Limnea peregra’s shell.
A

DELAYED CHROMOSOMAL INHERITANCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

a diffusible, hormone – like substance, involved in pigment synthesis

A

Kynurenin

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

depends on a gene pair in which the allele for dextral dominant.

A

Dextral-sinistral alternative

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

The developmental consequences of delayed gene action may also be detrimental e.g., grandchildless mutation in Drosphila.

  • Homozygous females are fertile, but the sex organs of their offspring fail to mature.
  • The offsprings are, therefore, all fully sterile, irrespective of the genotype of the male parent.
  • The effect of the grandchildless gene is transmitted through the egg cytoplasm where it acts to prevent normal reproductive development.
A

DELAYED CHROMOSOMAL INHERITANCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

There are cytoplasmic factors which are capable of self – perpetuation and independent transmission and are therefore considered genetic units fully equal to those in the chromosome.

A

EXTRACHROMOSOMAL INHERITANCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Because of their location outside the chromosome, these genetic factors have been called?

A

plasmagenes, or plasmons, or cytogens or plasmids.

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Extranuclear inheritance or inheritance through plasmids tends to be maternal because most of the zygote’s cytoplasm is derived from the egg. Therefore, reciprocal crosses give different results, a situation like delayed chromosomal inheritance.

  • The unusual phenotypic ratios do not disappear after one generation.
A

EXTRACHROMOSOMAL INHERITANCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Plasmid inheritance implies perpetuation through DNA replication; hence, it is a second system for the transmission of traits.

A

EXTRACHROMOSOMAL INHERITANCE

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q
  • In Chlamydomonas – a single celled green alga, Sager and her co – workers found in 1960 a number of hereditary variables that failed to show segregation in a chromosomal pattern.
  • For example, streptomycin resistance (sr) or sensitivity (ss) appears to be inherited in a regular Mendelian fashion so that sr x ss produces 1⁄2 sr and 1⁄2 ss offspring.
A

Cytoplasmic Inheritance

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

a single celled green alga, Sager and her co – workers found in 1960 a number of hereditary variables that failed to show segregation in a chromosomal pattern.

A

Chlamydomonas

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Sonneborn in 1943 studied the inheritance of the killer vs. sensitive trait in Paramecium aurelia.

  • He found that to be a killer, a Paramecium must have the gene K (which segregates in the typical chromosomal fashion), and a complement of cytoplasmic particulate material called kappa.
  • Sensitive animals are those that lack of kappa.
A

Cytoplasmic Particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Sonneborn in 1943 studied the inheritance of the killer vs. sensitive trait in?

A

Paramecium aurelia

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

He found that to be a killer, a Paramecium must have the gene K (which segregates in the typical chromosomal fashion), and a complement of cytoplasmic particulate material called

A

Sonneborne; kappa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Sensitive animals lack of what?

A

kappa

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Its pigment that kappa utilizes in oxygen respiration are different from those of the host. Therefore, since Paramecium exists quite well without kappa, its presence seems to be of an accessory organism or symbiont.

A

Cytochrome

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Killer animals could maintain as many as 1600 kappa particles, each measuring about 0.2 micron in diameter. Each kappa particle contains DNA, indicating some hereditary independence.

  • The cytochrome pigments that kappa utilizes in oxygen respiration are different from those of the host. Therefore, since Paramecium exists quite well without kappa, its presence seems to be of an accessory organism or symbiont.
A

Cytoplasmic Particles

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

These/this is/are responsible for photosynthesis

A

Chloroplasts

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

The structure of these organelles, the pigments contained, and their enzyme systems can all be affected by mutations indicating that chloroplasts are not free from chromosomal genetic apparatus control.

A

Chloroplast

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

They arise from pro –plastids, which can divide and structures, they are capable of self-replication.

A

Mature plastids

23
Q

Certain plastid differences are not transmitted along chromosomal lines.

  • Plastids contains DNA, it may then be concluded that plastids have a genetic machinery of their own, machinery that lies outside the chromosome e.g., variegated four o’clock (Mirabilis jalapa).
A

Chloroplast

24
Q

It contains DNA, it may then be concluded that _____ have a genetic machinery of their own, machinery that lies outside the chromosome e.g., variegated four o’clock (Mirabilis jalapa).

A

Plastids

25
Q

This petite characteristic is chromosomally determined trait— when crossed with the wild type, produce ascospores which segregate in the ratio 1 petite: 1 normal.

A

Segregational (nuclear) petites

26
Q

when mated with normal strains, will produce only normal or wild type ascorpores and colonies.

A

Neutral petites

27
Q

What test proved that the petite characteristic never reappears and seems to have been physically lost. This behavior indicates an extrachromosomal inheritance.

A

Heterokaryon test

28
Q

suppress normal respiratory behavior in crosses with the normal strains so that most of diploid cells derived from a zygote are petites.

A

Suppressive petites

29
Q

Most of them, when induced to sporulate in a special environment, give rise to asci with four petite spores. Therefore, acts as a dominant trait.

A

Suppressive petite factor

30
Q

It also have their own DNA and they have been known to divide or reproduce by themselves.

A

Mitochondira

31
Q

This continuity of the mitochondria and the mitochondrial DNA explains the cytoplasmic continuity of the neutral and suppressive petites.

A

Mitochondria

32
Q

GENETIC DISORDERS IN HUMANS ASSOCIATED WITH MITOCHONDRIAL DNA (description)

A
  • The human mitochondrial genome includes only 37 genes.
  • Thirteen encode proteins. The gene are important in cellular respiration.
  • In 1988, the first human genetic disorder associated with mitochondrial mutation was identified.
  • Hereditary mitochondrial diseases are transmitted only through the maternal line, since spermatozoa contain hardly any mitochondria.
  • Progressive external opthalmoplegia – gradual loss of the ability to control eye movement.
33
Q

How many genes does the human mitochondrial genome includes/contains?

A

37 genes

34
Q

When was the first human genetic disorder associated with mitochondrial mutation identified?

A

in 1988

35
Q

are transmitted only through the maternal line, since spermatozoa contain hardly any mitochondria.

A

Hereditary mitochondrial diseases

36
Q

gradual loss of the ability to control eye movement.

A

Progressive external opthalmoplegia

37
Q

progressive external opthalmoplegia, pigmentary disorders in the eyes, heart disease, cerebellar dysfunction, high cerebrospinal fluid protein, muscle weaknesses, hearing loss, diabetes.

A

Kearn – Sayre Syndrome

38
Q

occurs during childhood characterized by a combination of symptoms like anemia, reduction in the numbers of all blood cells, dysfunction of the pancreas, liver and kidneys.

A

Pearson Syndrome

39
Q

degeneration of the optic nerve that causes rapid onset of blindness (usually in men in their 20s).

A

Leber Hereditary/ Optic Neuropathy

40
Q
  • Two major hypotheses have been proposed to explain heterosis: First the dominance hypothesis which states that there is accumulation of favorable parental dominant genes in the hybrid parental.
  • The second one is the overdominance hypothesis, the heterozygotes are more vigorous, productive, and perform well over a range of environments than either homozygotes.
A

Cytoplasmic – Nuclear Male Sterility

41
Q

Cytoplasmic – Nuclear Male Sterility

A
  • Without CMS, hybrid seed production requires emasculation/disabling of pollen before anther dehiscence and stigma receptivity. It means disabling of young male
    inflorescence.
  • Using CMS lines as the female parent restorer line (R line) as the male parent, the tedious process of emasculation/ detasseling is bypassed in the F1 hybrid seed production.
42
Q

PLASMIDS OF EXTRACELLULAR ORIGIN
Three important characteristics of these particles:

A
  1. They are not normal or indispensable components of the normal cell.
  2. They can be transmitted from infected to uninfected individuals by cell extracts from the former.
  3. They are not capable of moving in and out of the chromosomal DNA of the host and can exist in the nucleus of the cytoplasm of the host.
43
Q

This has been shown in a wide variety of organisms.

  • For example, females of certain strain of mice are particularly susceptible to mammary cancer, while other strains are resistant.
A

Infective heredity

44
Q

The cause CO2 sensitivity is a virus – like particle called?

A

sigma.B

45
Q

sensitivity is a heritable trait, but the transmission is through the maternal line.

A

CO2

46
Q

The transmission behavior of sigma shows that it requires a nuclear gene before its life cycle may continue. Also, sigma is not infective in other insect genera, indicating its dependence on appropriate genes.

A

Infective Heredity

47
Q

Are genetic elements (DNA molecule) that may exist either as an integral part of a chromosomal DNA molecule of the host or as an independently replicating DNA molecule (plasmid), free of the host chromosome. These genetic elements are also ineffective.

A

Episomes

48
Q

CRITERIA FOR EXTRACHROMOSOMAL INHERITANCE

A
  • The pattern of transmission for a phenotype based on any of the various potential extranuclear systems cannot be predicted with certainty.
  • The most feasible procedure is to examine whether there are instances where transmission is such that the chromosomal basis is either ruled out or at least unlikely. Where such systems occur, one can examine whether particular extranuclear systems are implicated.
49
Q

CRITERIA FOR EXTRACHROMOSOMAL INHERITANCE

A
  1. Difference in reciprocal cross results
  2. Maternal Inheritance
  3. Non – mappability
  4. Non – Mendelian Segregation
  5. Indifference to nuclear substitution
50
Q

When one follows the transmission of characteristics based on chromosomal heredity, the reciprocal crosses are ordinarily identical, except in cases of sex-linked genes.

A

Difference in reciprocal cross results

51
Q
  • A characteristics form of difference in the results of reciprocal crosses is a maternal inheritance, where the progenies show the characteristics of their female parent.
  • If the chromosomal differences can be ruled out, maternal inheritance usually implies transmission through the cytoplasm.
  • This is because the female gamete ordinarily provides more cytoplasm to the zygote than the male genome does.
A

Maternal Inheritance

52
Q

If the chromosomes of an organism are well – mapped, a characteristic based on chromosomal heredity should show linkages and should be mapped in reference to other gene -controlled characteristics.

A

Non – mappability

53
Q

When the segregation occurs in a fashion inconsistent with chromosome segregation, non – chromosomal factors might have accounted for the phenotypic variations.

A

Non – Mendelian Segregation

54
Q

When a heritable characteristic persists in the presence of nuclei known to have been associated with alternative characteristics, the control of the nuclear genetic material over the characteristic may be ruled out.

A

Indifference to nuclear substitution

Genetics (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2024 Bold Learning Solutions. Terms and Conditions