Brainscape's Knowledge GenomeTM

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


See full index

Bioscience 2 > Growth and Development of Organisms > Flashcards

Growth and Development of Organisms Flashcards

1
Q

What are the 5 key stages of the human life cycle?

A

Embryonic development –> Growth –> Puberty –> Maintenance –> Ageing

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

What is embryogenesis?

A

The formation and development of an embryo

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

When is an embryo structure formed?

A

The overall structure is formed by the first two months of pregnancy.

The rest of the gestation period is mostly growth (3cm - 5cm)

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

When does pregnancy begin?

A

Day 1 of the last menstrual period

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

What is the germinal period?

A

Week 0 - 4
just the egg

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

what weeks is a foetus formed?

A

3rd - 8th week

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

When is the first trimester?

A

Week 0 - 13

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

When is the second trimester?

A

Week 13 - 26

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

When is the third trimester?

A

Week 27 - 38

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

What is the critical period?

A

The developmental stage when an embryo is susceptible to toxic agents (teratogens)

Varies depending on organ but usually corresponds to the stage of active differentiation and morphogenesis

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

What are some possible teratogens? (toxic agents)

A

medications – e.g. thalidomide (sedative drug)
alcohol, tobacco, caffeine
environmental chemicals
viral infection

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

What is the critical period for the CNS in humans?

A

Week 3 - 16

(moderately sensitive till week 38)

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

What is the critical period for the heart in humans?

A

Week 3 - 8

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

What was the critical period of thalidomide?

A

day 34 - 51 (week 4 - 8)

  • mothers who took thalidomide in this period had babbies affected - born with major malformations
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

When does implantation occur?

A

Occurs at the blastocyst stage - day 8 - 9 after fertilisation.

Once implanted the embryo develops, embryonic disk is formed - one layer of cells - cells then proliferate

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

What are the 3 germ layers formed following gastrulation (when the blastocyst has formed)?

A

Ectoderm - smaller top layer
Mesoderm - middle layer
Endoderm - large bottom layer

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

What is the derivative of the ectoderm?

A
  • surface ectoderm (epidermis of skin)
  • nervous system
  • neural crest cell derivatives
18
Q

What is the derivative of the mesoderm ?

A
  • Dermis ( inner layer of skin)
  • Muscles
  • Skeleton
  • Urogenital organs (except urinary bladder)
  • Blood, vasculature, spleen
19
Q

What is the derivative of the endoderm?

A
  • digestive system (gut, liver, pancreas)
  • respiratory system
  • urinary bladder
  • thyroid, parathyroid
20
Q

What is the main function between week 0-10 in the gestational period?

A

Morphogenesis and Differentiation

21
Q

What is the main function between week 10-20 in the gestational period?

A

Rapid growth

22
Q

What is the main function between week 20-30 in the gestational period?

A

Protein accumulation

23
Q

What is the main function between week 30-40 in the gestational period?

A

Fat accumulation

24
Q

What hormones are involved in growth?

A
  • Growth hormone (GH)
  • Insulin - like Growth Factor - 1 (IGF-1)
  • Gonadotrophin releasing hormone (GnRH)
  • Gonadal steroids ( Androgens, Oestrogens, Progesterone)
  • Others ( Thyroid hormones, calcitonin, parathyroid hormone, corticosteroids)
25
Q

What are the effects of growth hormone (GH)?

A

Stimulates glycogenolysis by the liver –> raises plasma glucose level –> makes glucose available for glycolysis

Represses glucose uptake by muscles and adipose tissue

Stimulates lipolysis

Stimulates amino acid uptake –> protein synthesis

Causes production of IGF ( insulin like growth factor in the liver

26
Q

What is the effect of GnRH? (gonadotrophin releasing hormone)

A

Increases hypothalamic GnRH secreting neurones activity

= increase of FSH and LH up to age 10
(follicle stimulating hormone and luteinising hormone)

= puberty

  • In females, ovarian follicles begin to mature
  • In males Leydig cells mature in response to
    LH –> testosterone secretion,
    spermatogenesis
27
Q

How is the adult body maintained?

A

Through cell renewal

28
Q

What cells are renewed by stems cells?

A

Skin epidermis
Intestinal epithelium
Blood cells
Olfactory neurones (e.g. in rodents)

29
Q

What cells are renewed without stem cells?

A

Insulin producing Beta cells
Hepatocytes in the liver

30
Q

What cells do not renew?
(as known so far)

A

Auditory receptor cells (in the ears)
Photoreception cells (in the eyes)

31
Q

What are undifferentiated stem cells?

A

Lack tissue specificity or specialized functions

32
Q

What can stem cells that are able to differentiate do?

A

Give rise to specialised cell types via differentiation

33
Q

What are stem cells that are self renewing ?

A

Capable of renewing themselves by cell division for long periods

i.e undifferentiated state maintained after cell division in at least one daughter cell

34
Q

What embryonic stem cells?

A

Pluripotent - can differentiate into any part of the body

35
Q

What are adult stem cells?

A

Multipotent - can differentiate into more than one type of cell
But can only differentiate to a cell within the same lineage

36
Q

What are examples of adult stem cells?

A

Hematopoietic stem cells
Dermal papilla cells, hair follicle stem cells
Intestinal stem cells

Mesenchymal stem cells
Satellite cells - in muscles

37
Q

What are some of the factors of aging?

A
  • Reduction of hormones (GF, FSH, LH)
  • Accumulation of mutations and epigenetic changes in the genome
  • Accumulation of mutations in mitochondrial DNA
38
Q

What is quiescence?

A

Cell cycle arrest at G0 due to a lack of nutrition, no stimuli for cell divsion

39
Q

What is senescence?

A

Where cells go from G0 to cell death eventually even though the cells were metabolically active.

  • Because the chromosome becomes shorter and shorter at their ends (telomere)
  • Chromosome without telomere is detected as a DNA damage and cell cycle is stopped
40
Q

What is the importance of telomere in stem cell replication?

A
  • Telomere is a repetitive DNA sequence at the end of chromosomes - protects the chromosome from damage and end fusion
  • DNA replication of that region requires telomerase
  • Stem cells express high levels of telomerase so can replicate without a loss of the telomere region
  • Telomere shortening is a way for cells to count divisions. Getting rid of old cells and guarding against uncontrolled cell division

Bioscience 2 (21 decks)

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