All NCERT Examples- Biology Class 12

rice, wheat

30 minutes pollen viability

leguminoseae, rosaceae

months pollen viability

papaver

syncarpous

michelia

apocarpous

maize, castor

monoecy i.e. male and female flowers on same plant

papaya

dioecy i.e. male and female flowers on different plants

commelina, oxalis, viola

flowers with both chasmogamous and cleistogamous flowers

Amorphophallus

tallest flower

corn cob

large inflorescence for anemophilly

60

pollen at 2 cell stage percent

30

how many species hydrophilly

water lily, water hyacinth

aquatic plants with anemophilly

grasses

wind pollination common in

vallisneria, hydrilla (fresh water)

surface of water pollination

seagrasses like zostera (marine)

submerged pollination

bees

most common biotic pollinator

pea, groundnut, beans

endosperm consumed in

castor, coconut, wheat, maize, barley

persistent endosperm

grass

scutellum

pea, groundnut, beans

non albuminous seeds

coconut, castor, wheat, maize, barley

albuminous seeds

black pepper, beet

perisperm/ persistent nucellus

10 to 15 percent

how much water in seeds

apple, guava, mango orange

fleshy fruits

groundnut, mustard

dry fruits

cashew, apple, strawberry

thalamic fruits

lupinus arcticus from arctic tundra

oldest seed

citrus, mango

nucellar cells form embryo

4-5 cm

length of testis

2-3 cm

width of testis

2-4 cm

length of ovaries

10-12 cm

fallopian tube length

250

lobules per testis

2 to 3

seminiferous tubules per lobule

15 to 20

mammary lobes per breast

200 million

sperms per coitus

60 percent

normal shape sperms

40 percent

vigorous motility sperms

60,000 to 80,000

primary follicles per ovary

asteraceae, grasses

apomixis

1951

family planning initiated in

reproductive and child health care

RCH

14

how many varieties chosen by mendel

reginald c punnett

Punnett square by

flower color in dog flower (antirrhinum/ snapdragon)

incomplete dominance example

blood group

codominance example

6, 3

number of genotypes, phenotypes of blood group

blood group

multiple allele example

de vries, correns, von tschermak

rediscovered mendel's work

sutton, boveri

noticed chromosome behaviour was parallel to genes

sutton

chromosomal theory of inheritance given by

2 weeks

drosophilla completes life cycle in

drosophilla melanogaster

thomas hunt morgan worked on

thomas hunt morgan

linkage discovered by

yellow-bodied, white-eyed females to brown-bodied, red-eyed males

who did morgan cross

1.3 percent

recombination in white and yellow

37.2 percent

recombination in white and miniature wing

albert strutevant

mapped chromosome linkage

skin color

polygenic

phenylketonuria, starch synthesis in peas

pleiotropic

henking

discovered x chromosome, called it x factor

grasshopper

XO Type of sex determination

poultry

females have ZW in

cancer cells

chromosomal aberraations common in

phenyl alanine hydroxylase

phenylketonurea causes mutation in which enzyme

mental retardation, reduction in hair, skin pigmentation

symptoms of phenylketonurea

x linked recessive

haemophilia

autosomal dominant

Myotonic dystophy

autosomal recessive

sickle cell anaemia

x linked recessive

color blindness

replacement of glutamic acid by valine on 6th position of beta chain of haemoglobin

sickle cell anaemia caused due to

autosomal recessive

phenylketonuria

lack of enzyme that converts phenlalanine to tyrosine which causes phenyalanine accumulation as phenylpyruvic acid

phenylketonuria cause

autosomal recessive

thalassemia

reduced formation of one of the chains of haemoglobin

thalasemia cause

16

on which chromosome are hba1, hba2 responsible for alpha thalassemia

11

beta thalassemia with hba2 responsible for chromosome

extra copy of chromosome 21

downs syndrome due to

loss of an x chromosome

turners syndrome due to

extra x chromosome

klinefelter syndrome due to

3.3* 10^9

human dna nucleotides

5386

phi 174 nucleotides

48502

bacteriophage lambda nucleotides

4.6 * 10^6

e coli nucleotides

fredrich meischer

nuclein by

franklin, wilkins

watson and crick based on data by

3.4 nm

one turn length

0.34 nm

distance between 2 bp

francis crick

central dogma given by

200

bp in a nucleosome

fredrick griffith, streptococcus pneumoniae

transforming principle

hershey, chase

unequivocal proof

avery, mc leod, mc carty

biochem characterization of transforming principle

meselson, stahl

semiconsevative replication model

20 minutes

e coli divides in how much time

taylor et al

radioactive thymidine in vicia faba

gamow

codons theorised by

hargobind khorana

proof of codons existence

nirenberg

cell free system for protein synthesis

severo ochoa enzyme- polynucleotide phosphate

rna in template independent manner using