1. Chasmogamous flowers are the bisexual, open flowers with exposed anthers and stigma. 
2. Cross-pollination cannot occur in cleistogamous flowers because they remain in bud throughout their life and form seeds via self-pollination.

An embryo sac is called monosporic because it develops from one of the four megaspores formed from the division of megaspore mother cell.

Partiruition refers to the process of delivery if the fully-developed foetus,i.e.,childbirth.
Relaxin and oxytocin are the hormones involved in the process.

1. Apomixis is a form of asexual reproduction that mimics sexual reproduction and seeds are formed without fertilisation.
2. Apomictic embryos are genetically identical to the female parent.
3. If hybrid seeds can be made apomictic, the desirable characters can be maintained in the progeny.
4. It is often associated with polyembrony.

(i) Spermiogenesis is the process of transformation of spermatids into flagellated spermatozoa.
(ii) Spermiation is the process of release of spermatozoa from the seminiferous tubules.

There is an adaptation in angiospermic plants to provide assured nutrition to the developing embryo. Most zygotes divide only after certain amount of endosperm is formed. Therefore, zygote remains dormant for sometime in a fertilised ovule.

1. Male gametophyte - In the Anther (microsporangia) and later on the stigma and style.
2. Female gametophyte - inside the ovule.

Tapetum is the innermost layer of the microsporangium. It produces the exine layer of the pollen grains, which is composed of the sporopollenin, the most resistant organic material. During microsporogenesis, the cells of tapetum produce various enzymes, hormones, amino acids and other nutritious materials required for the development of pollen grains.

The male accessory ducts are rete testis, vasa efferentia, epididymis and vas deferens.These ducts store and transport the sperms from the testes to the outside through the urethra. The male accessory glands are paired seminal vesicles, prostate gland and paired Bulbourethral glands. The secretion of these glands forms seminal plasma, which is rich in fructose, calcium and certain enzymes. The secretion of Bulbourethral glands lubricates the glans penis.

Triple fusion:
It is  the process of fusion of three nuclei, two polar nuclei (fuse to form a diploid secondary nucleus) and a male gamete.
It occurs in the central cell of the embryo sac of the ovule of angiosperms.
Then nuclei involved are two polar nuclei and a male gamete.

Hormones controlling spermatogenesis.
Spermatogenesis is initiated by an increase in the secretion of GnRH (gonadotropin-releasing hormone) by the hypothalamus, at the age of puberty.
The increased levels of GnRH act on the anterior pituitary and stimulate it to secrete two gonaditropins namely:
(i) Follicle Stimulating Hormone (FSH) and
(ii) Luteinizing Hormone (LH).
LH acts o the Leydig cells and stimulates them to secrete testosterone.
FSH acts on Sertoli cells and stimulates them to secrete some factors which help in spermiogenesis.

(i) In coconut, endosperm formation is of nuclear type. The primary endosperm nucleus undergoes repeated nuclear division without cell wall formation.
(ii) Tender coconut is an endosperm. It is rich in nutrients like fats, proteins, carbohydrates, minerals, vitamins, etc. Hence, it is considered as a healthy source of nutrition.
(iii) Pea seeds are non-endospermic, while castor seeds are endospermic.

(a) sexually
(b) viviparous
(c) internal
(d) haploid
(e) diploid
(f) ovulation
(g) luteinising hormone
(h) syngamy
(i) ampullary-isthmic junction
(j) blastula
(k) umbilical cord.

(a) False
Androgens are formed by Leydig cells.
(b) True.
(c) False
Oogenesis takes place in the ovarian follicles.
(d) True
(e) False
Oogenesis occurs in the female embryo before birth but does not complete until puberty.
(f) True.
(g) True.

1. The ovule is attached to the placenta by a short stalk called funiculus.
2. The junction between the funiculus and the ovule, is called hilum.
3. The primordium of the ovule grows into a mass of cells, forming the nucellus, the main body of the ovule.
4. It becomes surrounded by two protective envelopes called integuments, which leave a small opening called micropyle, at the tip of the ovule.
5. The basal part of the ovule (opposite to the micropyle) is called chalaza. Cells of the nucellus are rich in reserve food materials.
6. There is a single embryo sac/female gametophyte in the nucellus; it has developed from a megaspore.
7. The embryo sac contains the following cells:
(i) Three antipodal cells at the chalazal end.
(ii) Three cells at the micropylar end, forming egg apparatus, which consists of two synergids and a female gamete.
(iii) Two nuclei in the central cell, called polar nuclei, which fuse to form a diploid secondary nucleus.

Meiosis occurs during sporogenesis.
The structure formed at the end are microspores and megaspores respectively.