Intraspecific incompatability can be overcome by

Which type of association is found in between entomophilous flower and pollinating agent?

Plants of which one of the following groups of genera are pollinated by the same agency?

Which one of the following is surrounded by a callose wall?

From among the sets of terms given below, Identify those that are associated with gynoecium.

Which among the following has 23 chromosomes?

The membranous cover of the ovum at ovulation is

During embryonic development, the establishment of polarity along anterior/posterior, dorsal/ventral or medial/lateral axis is called

Which one of the following statements about human sperm is correct?

In oogamy, fertilization involves

What is the position of plumlue in monocot embryo?

Give the name of the common function that cotyledons and nucellus perform

The path of sperm transport is given below. Provide the missing steps in the blank boxes.

Male and female gametes are  ________.(diploid/haploid)

Cervix contains the largest and the strongest sphincter in its wall. Give reason.

Name the pouch in which the human tests are present.

Name the cells that nourish the germ cells in the tests. Where are these located in the tests?

State one advantage and one disadvantage of cleistogamy.

Mention an advantage and a disadvantage of a cleistogamous flower.

Cleistogamous flowers of Commelina are invariably autogamous. Mention its one advantage and one disadvantage to the plant. 

Name the pollinating agent of flowers like Salvia, Nasturtium and sunflower. Give two favourable features of such a flower for pollination.     

Name the pollinating agents of flowers like maize and wheat. Give any two favourable features of such a flower.

Differentiate anemophilous and entomophilous flowers

Mention the reasons for difference in ploidy of zygote and primary endosperm nucleus in an angiosperm.

Match between the following representing parts of the sperm and the functions:

(a) Name the human embryonic stage shown below. Identify 'a' and 'b' in it.

(b) Mention the part of the above embryonic stage that forms the foetus.

Differentiate
(a) Morula and Blastula
(b) Blastulation and gastrulation
(c) Trophectoderm and ectoderm

Name the type od blastula present in following animals:
(i) Amphioxus
(ii) Reptiles, birds and prototherian mammals
(iii) Insects
(iv) Annelids, molluscs
(v) Frog

Match the items in Column (A) with Column (B). Each point in column (A) has minimum one match in column (B) and maximum two matches.

With the help of an example of each explain the following?
Apomixis, Parthenocarpy, Polyembryony.

Give a schematic representation, showing the events of spermatogenesis in human male.

Ramesh got a job in Mumbai but his family was still living in the village. One day, he received a letter from his father stating that he is planning marriage of her sister who will be fifteen years old in March. Ramesh did not like the idea of his father of arranging plan of his sister till she attains age of 18 years.
Read the above passage and answer the following questions:
(i) In your opinion, who is right Ramesh or his Father?
(ii) What is the right age of marriage for girls?
(iii) What are the risks involved in early marriage?

Given below is the diagram of a human ovum surrounded by a few sperms. Observe the diagram and answer the following questions:

(a) Compare the fate of sperms shown in the diagram.
(b) What is the role of zona pellucida in this process?
(c) Analyze the changes occurring in the ovum during the process.
(d) How is the entry ofsperm into the ovum facilitated?
(e) Specify the region of female reproductive system where the event represented in the diagram takes place

During the reproductive cycle of a human female, when, where and how does a placenta develop? What is the function of placenta during pregnancy and embryo development?

The following is the illustration of the sequence of ovarian events "a" to "i" in a human female:

(a)Identify the figure that illustrates corpus luteum and name the pituitary hormone that influences its formation.
(b) Specify the endocrine function of corpus luteum. How does it influence the uterus? Why is it essential ?
(c)What is the difference between "d" and "e"?
(d) Draw a neat labelled sketch of Graffian follicle.

Nisha's grandmother often blames her mother for giving birth to 3 daughters and no son and therefore wants another marriage of her son. Answer following questions on the basis of above information.
(i) Is it right to blame a female for determination of sex and giving birth to only girls? Justify.
(ii) What values are not exhibited by Nisha's grandmother.